A. Field of the Invention
The present invention relates to golf clubs. More particularly, the invention relates to an improved golf putter having an interchangeable rebound control insert.
B. Description of Background Art
In theory, golf is a simple game, merely requiring that the player advance a ball from a tee located at the beginning of a fairway into a cup or "hole" located on a green at the end of a fairway, by successively hitting the ball with selected clubs a minimum number of times, or strokes. This progression from tee to green is repeated for the nine or eighteen seriatim fairways or holes which the particular golf course is segmented into. In practice, however, the game of golf can be very frustrating, for a number of reasons.
For long "holes," beginning golfers frequently experience problems with their "long game," i.e., have difficulty in hitting the ball squarely with sufficient force to traverse the fairway from tee to green with a minimum number of strokes. However, for most people that are not physically handicapped, a facility for hitting "long" balls can be developed in a relatively short time, by practicing at driving ranges, for example. On the other hand, beginning golfers often find that, although the skills required to advance the ball from the tee to the vicinity of the green in a reasonable number of strokes can be achieved in a relatively short time, "holing" the ball in the cup can add sufficient strokes to far exceed "par," the idealized, average number of strokes determined to be achievable by expert golfers playing the same hole.
Oftentimes, beginning golfers add excessive strokes to their game because of difficulties experienced in putting the ball into the cup from distant locations on the green. Putting difficulties can arise from the fact that a different set of motor skills are required for putting than for driving the ball from the tee, or hitting long fairway shots. The latter require expenditure of substantial amounts of kinetic energy by the golfer in imparting enough momentum to the ball to propel it for long distances. In putting, raw power or brute force is ineffectual, and the beginning golfer must acquire a substantial amount of finesse in hitting a ball residing on the green, to avoid overshooting the cup and adding unwanted strokes to his game.
Since the amount of momentum that must be imparted to a putted ball is so much less than required to drive a ball appreciable distances, beginning golfers often "pull" their club on short putts, i.e., fail to follow through on their stroke. This pulling or "choking" is detrimental, since the directional control of the impacted ball is adversely affected by such actions. Accordingly, many beginner golfers are confronted with the frustrating situation of putting the ball with good accuracy but beyond the cup, when utilizing their newly acquired skills for long-ball hitting with appropriate follow-through in their stroke. Conversely, choked or pulled strokes can result in the putted ball stopping short of the cup, or deviating substantially away from the cup.
The putting difficulties alluded to above are exacerbated by the substantial variations normally encountered in the conditions of greens. Thus, greens on which the grass is closely trimmed and dry offer minimum rolling resistance to a golf ball, and are "fast." Conversely, greens on which the grass is long and/or wet present substantial rolling resistance to a rolling golf ball, and are "slow." Therefore, the exact amount of momentum that must be delivered to hole a ball varies substantially as a function of green conditions, as well as with distance from the cup.
In recognition of the problems encountered with putting by beginners as well as even relatively experienced golfers, the present inventor disclosed a novel putter design to improve putting skills, in U.S. patent application Ser. No. 08/416,135 filed Apr. 5, 1995, now U.S. Pat. No. 5,458,332, issued Oct. 17, 1995, for a Golf Putter Head With A Cushioning Face. That application discloses heads having on the front face thereof a polymer pad having a rebound factor directly related to the distance to an intended target. For short putts and/or fast greens, a small rebound factor of, say 12.5% was disclosed as being desirable for putts of about 10 feet, 25% for 15-20 foot putts, 37.5% for putts of about 30 feet, and 50% for putts of 40 feet or greater.
By selecting a particular putter from a series of putters fitted with inserts having different rebound factors, the disclosed invention enabled golfers to utilize strokes that varied over a smaller power range, even for widely varying putting distances and green conditions. For example, by using a putter having an insert with a low rebound factor of 12.5%, the ball may be struck with nearly the same vigor for a 10 foot putt as for a 40 foot putt using a putter having a higher rebound factor of 50%. Therefore, the player can use a complete stroke with the follow through required for accurately launching the ball towards the cup, even for short putts and/or fast greens, by using a putter having an insert with an appropriately low rebound factor.
In addition to the substantial contribution to improved putting afforded by putters having inserts with rebound factors optimized to various putting situations, the present inventor's prior application disclosed putters in which the rebound factor of an insert could be varied somewhat independently of hardness. This capability permits the feel of the club upon impacting the ball to be adjusted somewhat, thus allowing inserts with varying rebound factors to provide similar sensory feedback upon impacting a golf ball.
The golf putter heads described in the present inventor's U.S. Pat. No. 5,458,332 referred to above provided a substantial contribution to improving a golfer's putting performance. However, a problem still existed for golfers approaching the green.
In the "short" portion of a golf game, it is usually necessary to hit the ball onto the green from a fairway, rough or sand trap. Such locations are oftentimes well within a golfer's maximum distance hitting capability. Accordingly, clubs with an inclined front face that provide a substantial vertical component (loft) to the ball trajectory are often used in approaching the green. A high trajectory minimizes the likelihood of overshooting the green, and results in the ball impacting the green at a relatively steep angle, thereby minimizing roll away from the impact point. In spite of making a careful choice of the best club to prevent exceeding a desired horizontal range, many players are confronted in their short games with the same dilemma as in putting; namely, maintaining normal swing and follow through to achieve good trajectory direction, and possibly overshooting an intended impact point, or pulling the shot to decrease horizontal range, while adversely affecting angular or bearing accuracy, and/or falling short of a desired impact point.
In view of the problems alluded to above, it occurred to the present inventor that some of the novel improvements which he disclosed in his U.S. Pat. No. 5,458,332, for putters might be adapted to other varieties of golf clubs, including wedges and other irons, as well as woods. Such considerations were in part a motivation for further inventions by the present inventor, which were disclosed in U.S. patent application Ser. No. 08/543,813, filed Oct. 16, 1995, now U.S. Pat. No. 5,674,132 to be issued Oct. 7, 1997 for a golf club head with a rebound control insert.
In the course of applying the improvements in putter construction disclosed in the '332 patent to other types of golf clubs, it was found that the larger ball impact forces typically encountered in using the latter suggested a somewhat more rugged design, to ensure that the polymeric insert on the club face could be attached securely to a club head, and by a relatively simple manufacturing technique. As it turned out, the newly conceived design for improved woods and irons turned out to be advantageously useable with the putter head design previously disclosed by the present inventor.
The present invention was conceived of to provide a golf putter including a head provided with an insert which may be readily interchanged to provide different rebound factors and/or hardness. Different rebound factors may be selected to suit a player's particular putting style. For example, a consistently heavy hitter might choose a lower rebound factor, to avoid overstroking a hole. On the other hand, the same player might choose a higher rebound factor for use on a particular day at a particular course when the greens were slower, because the grass was wet and/or longer. Different hardness values may be selected to provide a different feel upon impacting a ball.